#include <atomic>
#include <chrono>
#include <iostream>
#include <string>
#include <sys/epoll.h>
#include <thread>
#include <vector>
#include <dirent.h>
#include <string.h>
#include <stdlib.h>

using namespace std;
using std::string;

using namespace std::chrono_literals;
using namespace std::chrono;

int main()
{
    string http = "https://192.168.234.1/ota/800_flymap_agent.xmp";

    cout << http << endl;
    printf("%s\n", http.c_str());

    http.erase(4, 1);               /* delete 's' */
    printf("%s\n", http.c_str());   // http://192.168.234.1/ota/800_flymap_agent.xmp
    
    http.erase(http.begin(), http.end());               /* delete all */
    printf("%s\n", http.c_str());
}
